Giant anomalous Hall effect from spin-chirality scattering in a chiral magnet

Abstract

The electrical Hall effect can be significantly enhanced through the interplay of the conduction electrons with magnetism, which is known as the anomalous Hall effect (AHE). Whereas the mechanism related to band topology has been intensively studied towards energy efficient electronics, those related to electron scattering have received limited attention. Here we report the observation of giant AHE of electron-scattering origin in a chiral magnet MnGe thin film. The Hall conductivity and Hall angle, respectively, reach $$40,000$$ 40 , 000 \u2009Ω −1 \u2009cm −1 and $$18$$ 18 % in the ferromagnetic region, exceeding the conventional limits of AHE of intrinsic and extrinsic origins, respectively. A possible origin of the large AHE is attributed to a new type of skew-scattering via thermally excited spin-clusters with scalar spin chirality, which is corroborated by the temperature–magnetic-field profile of the AHE being sensitive to the film-thickness or magneto-crystalline anisotropy. Our results may open up a new platform to explore giant AHE responses in various systems, including frustrated magnets and thin-film heterostructures. The anomalous Hall effect (AHE) due to electron scattering process is typically limited to a small magnitude. Here, the authors report giant AHE of electron scattering origin in a chiral magnet MnGe thin film, possibly due to skew-scattering via thermally excited spin-clusters with scalar spin chirality.